package com.qssoft.cqry.common.shardingsphere.ds;

import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Pointcut;
import org.aspectj.lang.reflect.MethodSignature;
import org.springframework.core.annotation.AnnotationUtils;
import org.springframework.core.annotation.Order;
import org.springframework.stereotype.Component;

import java.util.Objects;

/**
 * @program: qssoft-cqry
 * @description: 多数据源处理
 * @author: HuaQiao.Deng
 * @create: 2021-06-04 13:01
 */
@Aspect
@Order(1)
@Component
public class DataSourceAspect {

    //@within和@target的区别在于@within会对子类继承的方法生效，但是子类的其他方法或者子类重写了父类的方法就不会在生效。
    @Pointcut("@annotation(com.qssoft.cqry.common.shardingsphere.ds.DataSource)" + "|| @within(com.qssoft.cqry.common.shardingsphere.ds.DataSource)")
    public void dsPointCut() {
    }

    @Around("dsPointCut()")
    public Object around(ProceedingJoinPoint point) throws Throwable {
        DataSource dataSource = getDataSource(point);
        if (Objects.nonNull(dataSource)) {
            DynamicDataSourceContextHolder.setDataSourceType(dataSource.value().name());
        }
        try {
            return point.proceed();
        } catch (Exception ex){
            throw ex;
        }finally {
            // 销毁数据源 在执行方法之后
            DynamicDataSourceContextHolder.clearDataSourceType();
        }
    }

    /**
     * 获取需要切换的数据源
     */
    public DataSource getDataSource(ProceedingJoinPoint point) {
        MethodSignature signature = (MethodSignature) point.getSignature();
        DataSource dataSource = AnnotationUtils.findAnnotation(signature.getMethod(), DataSource.class);
        if (Objects.nonNull(dataSource)) {
            return dataSource;
        }
        return AnnotationUtils.findAnnotation(signature.getDeclaringType(), DataSource.class);
    }

}
